[Clamav-devel] [PATCH] do not split messages to stderr

[Denis Vlasenko]

Hi.

I run clamav from smtp daemon. All output of daemon itself
and all child processes is logged to a file. Thus, messages from
several processes are mixed together. This is not a problem
as long as each process emits each message line in one go
(in other words, in single write syscall).

clamav does not do this, and logging sometimes breaks:

LibClamAV Warning: ********************************************************
LibClamAV Warning: ***  This version of the ClamAV engine is outdated.  ***
LibClamAV Warning: *** DON'T PANIC! Read http://www.clamav.net/faq.html ***
LibClamAV Warning: smtpfront-qmail[17611]: bytes in: 0 bytes out: 23
tcpserver: end 17611 status 0
tcpserver: status: 24/25
tcpserver: status: 25/25
tcpserver: pid 17670 from 203.101.178.30
tcpserver: ok 17670 0:195.66.192.170:25 :203.101.178.30::1366
********************************************************
smtpfront-qmail[17635]: bytes in: 0 bytes out: 23

This happens because "LibClamAV Warning: " and "****************"
are fprintf'ed as two separate strings to stderr,
and stderr is unbuffered.

This is important to fix for me because I post-process logs
(I build SQL statements for a database of past mail).

Patch is attached, please apply.
--
vda

diff -urpN clamav-0.85.1.0.orig/libclamav/others.c clamav-0.85.1.z.cur/libclamav/others.c
--- clamav-0.85.1.0.orig/libclamav/others.c	Wed May 11 05:50:35 2005
+++ clamav-0.85.1.z.cur/libclamav/others.c	Tue May 24 10:20:35 2005
@@ -80,23 +80,33 @@ short cli_debug_flag = 0, cli_leavetemps
 
 static unsigned char oldmd5buff[16] = { 16, 38, 97, 12, 8, 4, 72, 196, 217, 144, 33, 124, 18, 11, 17, 253 };
 
+static char cli_buf[256];
+
 void cli_warnmsg(const char *str, ...)
 {
 	va_list args;
+	int sz = sizeof("LibClamAV Warning: ")-1;
+
+    memcpy(cli_buf, "LibClamAV Warning: ", sz);
 
     va_start(args, str);
-    fprintf(stderr, "LibClamAV Warning: ");
-    vfprintf(stderr, str, args);
+    vsnprintf(cli_buf+sz, sizeof(cli_buf)-sz, str, args);
+    cli_buf[sizeof(cli_buf)-1] = '\0';
+    fputs(cli_buf, stderr);
     va_end(args);
 }
 
 void cli_errmsg(const char *str, ...)
 {
 	va_list args;
+	int sz = sizeof("LibClamAV Error: ")-1;
+
+    memcpy(cli_buf, "LibClamAV Error: ", sz);
 
     va_start(args, str);
-    fprintf(stderr, "LibClamAV Error: ");
-    vfprintf(stderr, str, args);
+    vsnprintf(cli_buf+sz, sizeof(cli_buf)-sz, str, args);
+    cli_buf[sizeof(cli_buf)-1] = '\0';
+    fputs(cli_buf, stderr);
     va_end(args);
 }
 
@@ -105,9 +115,13 @@ void cli_dbgmsg(const char *str, ...)
 	va_list args;
 
     if(cli_debug_flag) {
+	int sz = sizeof("LibClamAV debug: ")-1;
+
+	memcpy(cli_buf, "LibClamAV debug: ", sz);
 	va_start(args, str);
-	fprintf(stderr, "LibClamAV debug: ");
-	vfprintf(stderr, str, args);
+	vsnprintf(cli_buf+sz, sizeof(cli_buf)-sz, str, args);
+	cli_buf[sizeof(cli_buf)-1] = '\0';
+	fputs(cli_buf, stderr);
 	va_end(args);
     } else
 	return;

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